强悍的电子邮件地址(email address)正则表达式

原始来源: RegexLib.com
修改后加入了两个新功能:
1,匹配类似 "lc <deerchao@xxx.com>" 这样的包含姓名的格式.
2,添加了四个命名组: name, email, user, domain. 这样可以方便取出相应的信息.

Regex re = new Regex(@"^((?'name'.+?)\s*<)?(?'email'(?>[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+\x20*|""(?'user'(?=[\x01-\x7f])[^""\\]|\\[\x01-\x7f])*""\x20*)*(?'angle'<))?(?'user'(?!\.)(?>\.?[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+)+|""((?=[\x01-\x7f])[^""\\]|\\[\x01-\x7f])*"")@(?'domain'((?!-)[a-zA-Z\d\-]+(?<!-)\.)+[a-zA-Z]{2,}|\[(((?(?<!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])[^\\\[\]]|\\[\x01-\x7f])+)\])(?'angle')(?(name)>)$", RegexOptions.Multiline | RegexOptions.ExplicitCapture);
MatchCollection mc = re.Matches(@"l c <abc@example.com>
Abc@example.com
aBC@example.com
abc.123@example.com
");
foreach (Match ma in mc)
{
  
}

原表达式的最大优点就是匹配能力强大,能吃下各种符合规范(RFC2882)的表达式.
匹配WikiPedia上的10/11个合法邮件地址格式,不合法的一个也不匹配:

Valid e-mail addresses

• abc@example.com
• Abc@example.com
• aBC@example.com
• abc.123@example.com
• 1234567890@example.com
• _______@example.com
• abc+mailbox/department=shipping@example.com
•  !#$%&'*+-/=?^_`.{|}~@example.com (all of these characters are allowed)
• "abc@def"@example.com (anything goes inside quotation marks)
• "Fred Bloggs"@example.com
• "%()[]\;:,<>"@example.com

Invalid e-mail addresses

• Abc.example.com (character @ is missing)
• Abc.@example.com (character dot(.) is last in local part)
• Abc..123@example.com (character dot(.) is double)
• A@b@c@example.com (only one @ is allowed outside quotations marks)
•  %()[]\;:,<>@example.com (none of the characters before the @ is allowed outside quotation marks)